Do Earthworms have hairs?

Hey–apparently I missed International Earthworm Day!  So–here’s something wormy for you.

A lot of people don’t realize that earthworms, like their cousins the polychaete worms, also have hairs on each segment.  Earthworms have tiny, hard to see bristles called setae. While you can’t see them easily, you can feel them–gently stroke a worm from tail to front, and you’ll quickly feel these little spiny setae.earthwormxs

Though earthworms have no bones, their segmented system of muscles enables them to alternate between being stubby and thick, and long and slender.  This, in conjunction with the setae, allow the worm to anchor themselves in the dirt, either holding themselves in place (if a bird is tugging), or providing an anchor to push against as they tunnel forward.

So, why are we talking about hairy worms?

In a previous post, I linked to an illustration of a worm, and asked if it might actually be a giant phallic extraterrestrial earthworm (you’ve been warned). Someone then suggested it was more properly a Polychaete. Au Contraire! Polychaetes usually have fleshy body extensions called parapodia surrounding their hairs.parapodia

So now you know.

Thanks to VisualInfo and Reefkeeping for images.

6 thoughts on “Do Earthworms have hairs?

  1. Once, when I was working at the Archbold Biological Station in Florida, a local guy brought an odd earthworm to the lab. He’d found it on the side of his garage climbing up the wall.

    I got out the key, and sure enough, the thing really was weird. An introduced Asian species with setae that ringed the body, allowing it a much better grip than the usual worms. I told him that it was a non-native species and that’s why it seemed different.

    But that wasn’t his question. He wanted to know if the worm was a sign of the coming Apocalypse.

  2. True. But it’s closer to that than a Polychaete.

    And hey, it’s an alien phallic worm! Why should it conform to earth classification? :D

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